Vodafone executive Gavin Darby has been drafted in to replace Pluthero, who was paid £2.8m last year but has presided over three profit warnings and a 70% fall in the company's share price since its demerger from sister company Cable & Wireless Communications in March 2010.

Over £620m of write-downs were announced on Tuesday, exceeding analyst expectations. They are likely to push CWW into a paper loss for the year. These include the marking down of Energis, a company which Pluthero sold to the group in 2005 for £670m, and Thus, the Scottish firm acquired for £330m in 2008.

Pluthero had only been in the chief executive role for four months and had been due to update the City on his new strategy for the group on the day his departure was announced.

He had been chairman from demerger but was forced to return to the chief executive role in the summer after Jim Marsh shouldered the blame for CWW's poor performance.

Having made his name creating the internet service provider Freeserve for Dixons group, before moving to Energis, Pluthero was tempted into taking the helm at Cable & Wireless Group for a turnaround in 2006 with a £220m private equity style reward scheme for directors and managers. The strategy did not translate into long term growth and Tuesday's results for the six months to 30 September delivered further bad news.

Revenues fell 4.5% on the same period last year to £1.072bn. Pre-tax profit nearly halved, from £64m to £35m.

Revenues from voice calls fell £59m to £450m, revenue from data traffic also fell, by £13m to £480m. Hosting revenues, from server and website storage and cloud computing, rose £21m to £142m.

Chairman John Barton reiterated guidance for the full year and said an interim dividend of 0.75 pence per share would be paid in January 2012 at a cost of £20m. All subsequent dividends have been cancelled until the company increases its free cashflow.

Barton said: "At the end of a turbulent period for Cable & Wireless Worldwide, we are pleased to announce trading results in line with market expectations. The board has appointed Gavin Darby as chief executive officer. Gavin will provide the longevity of leadership required, energy and fresh insight for the future."

Pluthero will step down from the board in December and leave the company in March next year. Darby joins on 28 November from his current role as Vodafone chief executive for the USA, Africa, India and China. He was previously head of Vodafone's UK business, and before that spent 15 years at Coca-Cola.

He said: "I am honoured to undertake the challenge of leading Cable & Wireless Worldwide. I am very excited by the prospects of returning the business to profitable growth and working with colleagues, customers and suppliers to realise the significant potential within the business."

The markets responded to the news by discounting CWW shares by 10%. Analyst Mark James at Liberum Capital explained the drop: "A revolving door of executives, no dividend anymore and no growth. We remain sellers."